ST. LOUIS -- A U.S. man who avoided prison because of a clerical error and led a law-abiding life for 13 years said he is overwhelmed by the support he's received since the story of his eventual incarceration became public.

Meanwhile, the Missouri attorney general signalled that he would look for a way to take Cornealious "Mike" Anderson's many years of clean living into account in attempting to resolve the "difficult situation."

Anderson was convicted in 2000 of armed robbery for holding up a restaurant manager in suburban St. Louis, Missouri. But he was never formally ordered to report for his 13-year sentence. So he never went and instead got married, learned a trade and raised several children.

When prison authorities realized their mistake last July, they took him into custody.

Anderson said he's been cheered by inmates and guards at the Southeast Correctional Center in Charleston, Missouri, after his story appeared this week in news accounts.

An online petition urging his release has collected nearly 30,000 signatures, and one of Anderson's attorneys said Friday that the office has been flooded with calls from people who feel he has been wronged.

"It's a little overwhelming and embarrassing to me, but I can't thank people enough," Anderson said in a telephone interview with The Associated Press. "Everybody here has been positive, the prisoners and the correctional officers. I've had other prisoners tell me it gives them hope."

When the orders to report to prison never came, Anderson suspected that his case had been overlooked and asked his former attorney what to do.

"He said it's a mistake, and they're going to figure it out -- be prepared to be taken into custody," Anderson recalled. "Day by day, month by month, year by year, time passed, and they never picked me up."

So Anderson went about his life, never trying to conceal his whereabouts or identity. He married, divorced, married again. He raised three children of his own and a stepchild, owned and operated three construction businesses. He coached his son's youth football team in Webster Groves, Missouri, outside St. Louis, and ran the video operation at his church.

In July, Anderson's sentence was supposed to end. When someone at the Missouri Department of Corrections tried to begin the process of releasing him from prison, the agency realized he had never been put behind bars.

Anderson said he was just getting up around 6:30 a.m. on a hot July day when he heard a bang on the front door.

"It was one of those, 'Hey, open up the door!' type knocks," Anderson said. "I said, 'Who is it?' They said, 'U.S. marshals. Open up, or we'll knock the door down."'

Anderson peered through the curtain and saw eight armed marshals.

"They had shields and helmets. They had the streets blocked off. I said, 'You've got the wrong person.' One of them said, 'You remember 13 years ago when you were supposed to be incarcerated?'

"It hit me like a brick wall," Anderson said.

Anderson, 37, was alone at the time except for his 2-year-old daughter. The marshals immediately took custody of the girl. By noon that day, Anderson was at a state prison in Fulton, Missouri. He stayed there until he was transferred to Charleston in November.

"It was a nightmare," Anderson said. "The only thing I could think about was my wife and my kids."

Attorney General Chris Koster said Thursday that his goal was to suggest a way for the court to balance the seriousness of Anderson's crime with the clerical error made by the justice system and Anderson's conduct since the robbery.

Jaime Halscott, another of Anderson's attorneys, said Gov. Jay Nixon's office has also been asked to consider commuting the sentence or pardoning Anderson. Nixon's spokesman did not immediately return a message on Friday seeking comment.

"He's been rehabilitated," Halscott said of Anderson. "There's no need to protect the community, and even if you want your pound of flesh, he's been in prison nine months. At the end of the day, there's no good argument that this man should be in prison."

Anderson's attorneys filed an appeal in February calling his imprisonment unfair and unjust. Attorney Patrick Megaro said the last time something like this happened in Missouri was 1912, and that person was not forced to serve his sentence.